Flexible aryl alkyl epoxy resins, their amine resin derivatives and their use in electrodeposition coatings

ABSTRACT

A series of oligomeric adducts of diols and diepoxides are disclosed which are precursors of amine resins for use in electrodeposition coatings. The adducts are epoxide-alcohol addition products of a polyaromatic and/or a mono-aromatic diol and a polyaromatic bis-glycidyl ether, and/or a monoaromatic bis-glycidyl ether and/or an alkoxy arylene bis-glycidyl ether, thioether or amine. The coatings which include amine resin, cross linking agent, grind resin and pigment exhibit excellent corrosion resistance.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 327,751, filled on Mar. 23, 1989, now U.S. Pat. No. 5,021,470,which was a divisional application of U.S. patent application Ser. No.077,492, filed Jul. 24, 1987, now U.S. Pat. No. 4,857,567.

BACKGROUND OF THE INVENTION

The present invention relates to epoxide compound resins which areoligomeric adducts of diols and diepoxides, to the amine resins thereof,and to compositions containing the amine resins which can be used inelectrodeposition baths to produce the corresponding hardened resincoatings.

Cathodic electrodeposition of a film composed of amine resin,crosslinker, pigment and other resinous components onto an electricallyconductive article is an important industrial process. It constitutesthe usual manner in which automobile and truck bodies as well asappliance and other large metallic surface bodies are undercoated withpaint. In addition to providing a painted surface, the resin systemsemployed protect the underlying metal surface from corrosion, impactdamage and other detrimental exposure to environmental conditions.

In performing the electrodeposition, the conductive article forms oneelectrode and is immersed in a coating bath made from an aqueousdispersion of the film forming resin and other components. An electricalcurrent is passed between the article and the counterelectrode in theelectrodeposition bath. A charge on the article causes deposition of theresins and other components in the bath so as to produce theelectrodeposit film. The deposited film is then baked or otherwisehardened to yield a coating of a substantially uniform thickness andprotective characteristics.

Generally, protection from environmental and other adverse conditions isaccomplished by designing into the coating resins such chemicalcharacteristics as adhesiveness, flexibility, strength, hardness andinertness toward reaction with environmental elements. Each of thesecharacteristics manifests itself in the protective properties of thehardened coating.

A number of advances in the protective properties of electrodepositresin systems have been described in the patent literature. For example,U.S. Pat. Nos. 4,104,147; 4,148,772; 4,420,574; 4,423,166; 3,962,165;4,071,428; 4,101,468; 4,134,816; 3,799,854; 3,824,111; 3,922,253;3,925,180; 3,947,338; 3,947,339, the disclosures of which areincorporated herein by reference, describe methods for improvement ofthe principal resin properties. The amine resin used in the coatingdisclosed in these patents can be flexibilized by extending themolecular length of the aromatic diepoxide starting material withpolyols, with polyamines, polyether polyols, polyester polyols and othersimilar types of extension agents. The amine group functionality ofthese amine resins can also be altered according to these patents todevelop protective properties. Additionally, the chemical structure ofthe resin cross-linking agent affects the protective propertiesaccording to these patents.

Generally, the electrodeposition bath will also contain pigment andpigment grind resins. These components are deposited as part of thecoating and design characteristics are also important for them. Suchpatents as U.S. Pat. Nos. 3,936,405 and 4,035,275, the disclosures ofwhich are incorporated herein by reference, as well as others describebeneficial characteristics for such grind resins.

It is also desirable to obtain as thick an electrodeposition coating aspossible. Several studies have been reported in which the hardenedcoating thickness has been increased over that of the typical 16 micronto 20 micron film thickness produced by so-called "standard build" amineresin/polyisocyanate compositions. U.S. Pat. No. 4,487,674 (thedisclosure of which is incorporated herein by reference), for example,discloses compositions for producing thick films which constitutecombinations of surfactants and the amine resins disclosed in theforegoing U.S. patents.

It has been found, however, that the electrodeposition coatingsdescribed in the prior art do not achieve high corrosion resistivity andthe adhesiveness for superior protection of today s vehicular bodies. Itis believed these problems are the result of a two-fold difficulty.While strength and rigidity characteristics are desirable designfeatures of principal resin system coatings, the incorporation ofappropriate chemical groups providing these characteristics oftenadversely effects the flexibility and adhesiveness of the coatings.Consequently a balance is typically obtained between strength/rigidityand flexibility/adhesiveness. As a result, the coatings described in theprior art do not exhibit both high corrosion resistance and highstrength characteristics.

Therefore, it is an object of the invention to design an amine resinsystem for use in an electrodeposition coating which is of high strengthwhile also being highly resistant toward corrosion of the underlyingmetallic surface It is further an object of the invention to design aprincipal amine resin that is flexible enough to provide a low meltviscosity and a low glass transition temperature so that uniformcoatings are produced. Yet another object of the invention is theimprovement of the coating adhesiveness toward the underlying substratesurface. Further objects of the invention will become apparent from thedescription of the invention presented herein below.

SUMMARY OF THE INVENTION

These and other objects are achieved by the invention which is directedto flexibilized epoxide compounds, their corresponding amine resins, aswell as principal resin emulsions and electrodeposition compositions,both being formed from the amine resins. The invention as well isdirected to a process for coating a metallic substrate which employs theelectrodeposition compositions as electrodeposition baths and articlesof manufacture produced according to this process.

The epoxide compounds of the invention are addition reaction oligomersof a diol monomer and a diepoxide monomer wherein the diol monomer ischosen from a group including Diol D1, Diol D2, and a mixture thereof,and the diepoxide monomer is chosen from a group including Diepoxide E1,Diepoxide E2, Diepoxide E3 and a mixture of any two or all three ofthese Diepoxides. The addition reaction oligomers have epoxide groups atboth termini. While the oligomer of Diol D1 and Diepoxide E1 isexcluded, the remaining twenty combinations of diol and diepoxidemonomers provide the twenty classes of addition reaction oligomers ofthe invention.

The diol monomers, Diol D1 and Diol D2, respectively have at least onearyl group between the two hydroxyls present.

The diepoxide monomers, Diepoxide E1, Diepoxide E2 and Diepoxide E3, arebis-glycidyl ethers respectively of Diol D1, a bis-(labile hydrogenfunctionalized) alkoxy arylene, and Diol D2.

The bis (labile hydrogen functionalized alkoxy) arylene used to formDiepoxide E2 is the monoaddition product of either Diol D1 or Diol D2and an alkyl or alkoxy alkyl heterocyclopropane wherein the heteroatomof the heterocyclopropane is an oxygen, sulphur or nitrogen, i.e. theheterocyclopropane is an epoxide, episulfide or aziridine. Accordingly,the liabile hydrogen functional group of the bis (labile hydrogenfunctionalized alkoxy) arylene is a hydroxyl, a thiol or a primary orsecondary amine resulting from the ring opening of theheterocyclopropane.

The addition reaction oligomers formed from the foregoing combinationsof diol and diepoxide monomers contain alternating monomeric units ofdiol and diepoxide, the hydroxy groups of the diol monomeric unitshaving reacted with the epoxide groups of the diepoxide monomeric unitsso as to open the epoxide ring and form a secondary alcohol group withinthe diepoxide monomeric unit and an ether linkage between the diol anddiepoxide monomeric units. In addition to the alternating sequence ofdiol and diepoxide monomeric units, the distribution of the mixture ofdiols, if used, and the distribution of the mixture of diepoxides, ifused, may be random or ordered. If a random distribution is present, theorder of differing diol and diepoxide monomeric units along the oligomerchain will be random. If an ordered distribution is present, theoligomer chain will comprise blocks of one of the Diols reacted with oneof the Diepoxides. These blocks will be coupled together to providealternating groups of the several blocks present.

The amine resins according to the invention are the reaction products ofthe foregoing twenty classes of epoxide compounds and an amine such asammonia, a mono- or poly-organic amine wherein the amine groups may beprimary, secondary, or tertiary or combinations thereof, a heterocyclicamine or mixture of the heterocyclic amine and the mono- or poly-organicamine. Also included are physical blends and chemical mixtures of theseamines.

The combinations of diol and diepoxide monomeric units within themolecular formulas of the amine resins of the invention contribute tohigh adhesiveness, high corrosion resistance, high impact strength ofthe coated hardened films of the invention. In addition, the amineresins display high flow characteristics and flexibility owing to thepresence of these combinations.

The principal resin emulsions according to the invention are formed bycombination of the amine resins, cross-linking agents, water and aneutralizing portion of a low molecular weight organic acid. Preferredembodiments of the cross-linking agents include a blocked organicpolyisocyanate and a poly (beta-hydroxy ester) as well as a poly(beta-alkoxy ester) compound.

The aqueous electrodeposition compositions according to the inventionare composed of a combination of the principal resin emulsions and apigment-grind resin formulation. The preferred grind resin employed inthe pigment-grind resin formulation is a quaternary ammonium salt or anesterified, alkoxylated aliphatic amine. Preferred embodiments of theaqueous electrodeposition compositions include those wherein the solidscontent is about 10% to about 60% by weight, the solids content beingadjusted by the addition of water; those wherein the ratio of weightpercentage of the pigment-grind resin formulation and the principalresin emulsion is from about 1:10 to about 2:5; and those wherein the pHof the composition is from about 2.0 to about 8.5. In addition, it ispreferred that the ratio by weight of the pigment to grind resin in thepigment-grind resin formulation is from about 2:1 to about 6:1.

The electrodeposition compositions are used according to the inventionto prepare electrodeposition baths for electrocoating of a metallicsubstrate, such as an automobile or a truck vehicle body. Theelectrodeposition compositions are diluted with appropriate aqueousmixtures of water, organic acid, flow agents, anti-pitting agents,coalescing solvents, film build additives, and other suitable additivesto achieve appropriate and desired coating appearance and qualities.

According to the invention, the process of electrocoating a metallicsubstrate in a cathodic electrodeposition bath is accomplished byforming the coating bath, connecting the metallic substrate as a cathodeto a DC electric circuit, immersing the substrate in the bath, passingan electric current through the substrate thereby depositing a film ofamine resin, cross-linking agent, pigment, grind resin and other bathadditives on the substrate, removing the substrate coated with the filmfrom the bath and baking the deposited film to produce a hardened,cross-linked resin coating on the substrate.

The invention further includes articles of manufacture producedaccording to the foregoing process of electrodeposition.

DETAILED DESCRIPTION OF THE INVENTION

The novel chemical character of the epoxide compounds according to theinvention manifests itself in desirable properties of the correspondingamine resin components used in the electrodeposition baths according tothe invention. The preferred and especially preferred embodiments of theepoxide compounds of the invention include thirteen and seven classesrespectively of resinous oligomer based on the monomeric content presentbetween the epoxy termini of the oligomers. The monomers used to buildthe oligomeric structure of the epoxide compounds include rigid andflexible diepoxides and lower and higher molecular weight aromatic diolswhich couple the diepoxides together.

In the especially preferred embodiments of the invention, the groups ofDiols and Diepoxides, which form the addition reaction oligomers, may bereacted in any of several combinations including:

I. A combination of Diol D1 and Diepoxides E1 and E2 (hereinafterdesignated as the D2E epoxide compound");

II. A combination of Diols D1 and D2 and Diepoxides E1 and E2(hereinafter designated as the 2D2E epoxide compound);

III. A combination of Diols D1 and D2 and the three Diepoxides E1, E2and E3 (hereinafter designated as the 2D3E epoxide compound);

IV. A combination of the two Diols D1 and D2 and Diepoxide E1(hereinafter designated as the 2DE epoxide compound);

V. A combination of Diol D1 and the three Diepoxides E1, E2 and E3(hereinafter designated as the D3E epoxide compound);

VI. A combination of Diol D1 and Diepoxides E2 and E3 (hereinafterdesignated as the DEE epoxide compound); and

VII. A combination of Diols D1 and D2 and diepoxides E2 and E3(hereinafter designated as the 2DEE epoxide compound).

Other preferred embodiments of the invention include addition reactionoligomers of the following combinations of diol and diepoxide monomers:

VIII. A combination of Diol D1 and Diepoxide E2;

IX. A combination of Diol D1 and Diepoxide E3;

X. A combination of Diol D1 and Diepoxides E1 and E3;

XI. A combination of Diol D2 and Diepoxide E1;

XII. A combination of Diol D2 and Diepoxide E2;

XIII. A combination of Diol D2 and Diepoxide E3;

XIV. A combination of Diol D2 and Diepoxides E1 and E2;

XV. A combination of Diol D2 and Diepoxides E1 and E3;

XVI. A combination of Diol D2 and Diepoxides E2 and E3;

XVII. A combination of Diol D2 and Diepoxides E1, E2 and E3;

XVIII. A combination of Diols D1 and D2 and Diepoxide E2;

XIX. A combination of Diols D1 and D2 and Diepoxide E3;

XX. A combination of Diols D1 and D2 and Diepoxides E1 and E3.

The Diols used as monomeric units of the epoxide compounds and amineresins of the invention are calculated to provide interatomic distancesbetween the hydroxyls such that the portions of hydroxyl groups permolecular weight in the resulting amine resin are increased over thestandard amine resins known in the art. It is believed thischaracteristic contributes to the adhesiveness of the films of theinvention toward the metallic substrate.

Generally, the structure of Diol D1 may constitute any bis-(arylalcohol) compound known in the art. Its preferred embodiments have theformula HO-Ar¹ -OH, Ar¹ being a naphthalene group or a polyphenylenegroup having two or three phenylenes linked by carbon-carbon bonds oralkylene groups of 1 to 5 carbons, or a substituted derivative of thenaphthalene or polyphenylene group, the substituent being halogen,alkoxy of one to six carbons (lower alkoxy), or alkyl of one to sixcarbons (lower alkyl).

Diol D2 generally is any monoaryl diol known in the art. Its preferredembodiments have the formula HO-Ar³ -OH, wherein Ar³ is a phenylene orsubstituted phenylene group having as a substituent halogen, alkoxy ofone to three carbons, or alkyl of one to three carbon atoms.

Examples of Diol D1 include p,p'-dihydroxydiphenylalkane of 1 to 3carbons, p,p'-dihydroxydiphenyl, 1,5-dihydroxynaphthalene,bis-(hydroxynapthalene)methane, p,p'-dihydroxybenzophenone, thesubstituted forms of the foregoing examples wherein the substituent ishalogen, or alkyl or alkoxy of one to three carbons as well as otherpolyphenols and poly(hydroxyaryl) compounds of a similar nature.Additional examples of polyphenol compounds which can be used as Diol D1may be found in U.S. Pat. Nos. 4,605,609 and 4,104,147, the disclosuresof which are incorporated herein by reference.

Examples of Diol D2 include resorcinol, hydroquinone or catechol as wellas the substituted forms thereof wherein the substituent is halogen orlower alkyl, lower alkoxy, as well as additional mono aromatic diolsknown to those skilled in the art.

The general structures of the diepoxides used as diepoxide monomericunits of the epoxide compounds and amine resins of the invention are thebis-glycidyl ethers of Diol D1 or D2 or the bis-labile hydrogenfunctionalized alkoxy arylene compounds. The aliphatic character of theDiepoxide E2 monomer is believed to provide, in part, a flexiblecharacter to the epoxide compounds and amine resins. The aliphaticnature of this diepoxide monomer also is believed to contribute, inpart, to a lowered glass transition temperature and a lower meltviscosity of the amine resins. The Diepoxide E1 and E3 monomers, incontrast, are believed to contribute, in part, to the rigidity andstrength of the amine resins.

Preferred embodiments of Diepoxide E1 have the formula: ##STR1## whereinAr¹ is as defined above for Diol D1.

Preferred embodiment of Diepoxide E2 have the formula: ##STR2## In theformula for Diepoxide E2, R¹ is an alkyl of one to eight carbon atoms oran alkoxy alkyl of two to eight carbon atoms X is --O--, --S-- or═N--R², R² being hydrogen or alkyl or 1 to 3 carbons. Ar² is anaphthalene group, a phenylene group or a polyphenylene group having twoor three phenylenes linked by carbon-carbon bonds, or alkylene groups ofone to five carbons or a substituted derivative of naphthalene,phenylene or polyphenylene group, the substituent being halogen, alkoxyof one to three carbons or alkyl of one to three carbons.

In its preferred embodiment, the bis-(labile hydrogen functionalizedalkoxy)arylene, which is a precursor for the preparation of Diepoxide E2has the following formula wherein R¹, X and Ar² are as defined above forDiepoxide E2. ##STR3##

Preferred embodiments of Diepoxide E3 have the formula: ##STR4## whereinAr3 is as defined above for Diol D2.

The syntheses of the diepoxide compounds follow procedures known in theart. In such fashion, epihalohydrins such as epichlorohydrin,epibromohydrin or epiiodohydrin are reacted with the diol precursors toform the bis-glycidyl ether. Reaction conditions include use of anaprotic, polar solvent and an acid scavanger such as aqueous sodiumhydroxide or other similar hydroxide base under about stoichiometricproportions and a temperature of from about 0° C. to about 100° C.,preferably about ambient temperature.

The synthesis of the bis-(labile hydrogen) precursor for Diepoxide E2 isprepared by addition of either of Diols D1 or D2 to an alkyl oralkoxyalkyl monoepoxide, monoepisulfide or monoaziridine (i.e.heterocyclopropane wherein the heteroatom is --O--, --S-- or ═N--).Reaction conditions include an inert, organic solvent and catalyst suchas a quaternary ammonium salt or a Lewis acid under about stoichiometricproportions and a temperature of from about 0° C. to about 100° C.,preferably ambient temperature. These conditions will facilitate ringopening and an addition of the alcohol groups of the diol to theepoxide, episulfide or axiridine ring.

The alkyl or alkoxyalkyl monoepoxide, monoepisulfide and monoaziridinecan be prepared by reaction of the corresponding aliphatic olefin oralkoxy aliphatic olefin and an oxygen, sulfur or nitrogen producingagent. Such agents include per acids such as peracidic or perbenzoicacid, sulfur dichloride, and nitrenes generated from the correspondingazides. These reactions are generally known in the art. See, forexample, U.S. Pat. No. 4,284,574, the disclosure of which isincorporated by reference.

The two Diols D1 and D2 and the three Diepoxides E1, E2 and E3 arecombined according to the invention in any of several combinations toproduce the epoxide compounds of the invention. The sequence of diol anddiepoxide monomers in the addition reaction oligomer chain alternates,and the distribution of diepoxide monomers and diol monomers, when morethan one of each is present, may be random or ordered as mentionedabove. In producing a random distribution, the diol and diepoxidemonomers are combined as a gross mixture at the beginning of thereaction. In producing an ordered distribution of diol and diepoxide,monomer addition will be sequential so that a block of the first dioland a particular diepoxide will first be produced and then a second dioland diepoxide will be added to form second blocks grafted to the firstblock.

The proportion of each differing diol and diepoxide monomeric unitpresent in the addition reaction oligomers may vary from about a twopercent equivalent to about a 98 percent equivalent, the equivalentbeing determined by dividing the molecular weight of the diol ordiepoxide by the number of hydroxyls or epoxide groups respectivelypresent. Preferred proportions for diol monomeric units, when a mixtureof Diols D1 and D2 is combined, may be from one quarter to almost 100percent equivalent of Diol D2. Preferred proportions for the diepoxidemonomeric units, when a mixture of Diepoxides is combined, is fromtwenty percent equivalent to about ninety percent equivalent ofDiepoxide E1, ten percent equivalent to about ninety-five percentequivalent of Diepoxide E2, and five percent equivalent to about sixtypercent equivalent of Diepoxide E3. Appropriate adjustment of theproportion of the remaining Diol and Diepoxide of the mixture beingemployed is made to yield an equivalent proportion of 100 percent fordiol monomer and diepoxide monomer. The ratio of diol monomer totalequivalent to diepoxide monomer total equivalent is preferred to beslightly less than a stoichiometric equivalent of diol monomer totalrelative to the diepoxide monomer total so that epoxide groups terminatethe epoxide compound.

The oligomeric molecular weight of the epoxide compounds will be fromabout 900 to about 4000. The ratio of the sum of diol monomerequivalents to the sum of diepoxide monomer equivalents used for theaddition reaction to form the oligomers will be calculated so as toyield a molecular weight within this range. The equivalence of diol ordiepoxide is calculated by dividing the molecular weight of diol orepoxide by the number of hydroxyl or epoxide groups present in therespective molecule. The range of equivalent diol:diepoxide ratiosappropriate for generation of this molecular weight range will be from1:1.2 to 1:3. The preferred molecular weights lie in the range of fromabout 1800 to 2800 and especially preferred are molecular weights ofabout 2000 to 2500. The ratio of diol to diepoxide equivalents whichproduces these preferred molecular weights will be from about 1:1.4 to1:1.6. Appropriate adjustment of the ratio and reaction conditions willalso effect the molecular weight and sequence of the diols anddiepoxides present in the oligomers. Those of skill in the art willunderstand the variations and the effects they have upon the oligomericcharacter.

Generally the extent of addition will increase with both the time andtemperature of the reaction so that the desired molecular weight will beachieved through use of periods of about 2 to 4 hours and temperaturesof about 140° to 170° C. However, the reaction usually is self-limitingso that further time or temperature adjustment will not increase thelimiting molecular weight.

Lewis bases are generally used as catalysts to promote the addition ofthe diol monomers to the diepoxide monomers. It is preferred to use atriaromatic phosphine such as triphenyl phosphine as well as tetraalkylphosphonium salts.

General organic solvents typically are used as a reaction medium for theproduction of the addition reaction oligomer epoxide compound. Includedare such exemplary solvents as aliphatic ketones, for example methylethyl ketone or methyl isobutyl ketone as well as aromatic solvents liketoluene or xylene, polyethers and glycol ethers, and also alcohols.

According to the invention, the epoxide compounds are converted to thecorresponding amine resins which constitute one of the four primarycomponents of the electrodeposition compositions. The amine resins areformed by reaction of an amine with the epoxide compounds. The amineopens the epoxide rings and forms a terminating group thereon which willact as a protonation and solubilization site for the amine resins.

The especially preferred embodiments of the amine resins constitute thefollowing series of compounds.

I. The D2E amine resin is produced from reaction of the D2E epoxidecompound.

II. The 2D2E amine resin is produced from reaction of the 2D2E epoxidecompound.

III. The 2D3E amine resin is produced from the reaction of the 2D3Eepoxide compound.

IV. The 2DE amine resin is produced from the reaction of the 2DE epoxidecompound.

V. The D3E amine resin is produced from the reaction of the D3E epoxidecompound.

VI. The DEE amine resin is produced from the reaction of the DEE epoxidecompound.

VII. The 2DEE amine resin is produced from reaction of the 2DEE epoxidecompound.

In similar fashion, the preferred embodiments of the amine resins of theinvention constitute the reaction products of the preferred epoxidecompounds and an amine.

The diepoxide and diol monomeric units present in the amine resinscontribute adhesiveness, strength and flexibility to the amine resinswhen they are deposited on the substrate surface. These monomeric unitsalso contribute to a more uniform flow of the coating during baking andbond the film to the substrate. In general, it is believed that thebackbone structures of the epoxide compounds (i.e., the precursors forthe amine resins) and the corresponding amine resins are substantiallylinear and the pendant groups, e.g., R¹, provide moderate side chainsteric interaction; however, little if any polymeric branching ispresent. The combination of a linear backbone and side chain branchingcharacter is believed to contribute in part to the flexibility, loweredglass transition temperature and lowered melt viscosity of the amineresins of the invention.

The kinds of amines useful for formation of the amine resins includeammonia, and mono- and poly- primary, secondary, and tertiary amines aswell as mono- and poly- amines containing mixtures of primary, secondaryand tertiary amine groups. Heterocyclic amines and physical blends orchemical mixtures of these amine embodiments may also be used.Optionally, these amines may contain other functional groups such ashydroxyl, amide, carboxylic acid, ether, thio, thioether or alkoxygroups. The amine may preferably contain from one to five amine groups.When tertiary amine groups are present, primary or secondary aminegroups will also preferably be present. The organic radicalssubstituting the mono or poly- primary, secondary or tertiary amine maybe aliphatic, saturated, unsaturated, aromatic or alkaromatic alicyclicaromatic-substituted aliphatic, aliphatic-substituted aromatic orheterocyclic in nature. Generally, the aliphatic groups may be alkyl oralkenyl groups having from one to ten carbon atoms. The aromatic groupsmay be mono or polyphenylene groups or naphthalene groups havingoptionally substituted thereon one or more lower alkyl or lower alkoxygroups. When polyamines are employed, amine groups may both terminatethe amine compound and may be present within the chain structure of theamine compound. Exemplary of suitable aliphatic and alicyclic diaminesare the following: 1,2-ethylene diamine, 1,2-propylene diamine,1,8-menthane diamine, isophorone diamine, propane-2,2-cyclohexyl amine,and triethylene tetramine.

Mixed amines in which the radicals are different such as, for example,aromatic and aliphatic can be employed and the other optional groupsmentioned above can be present attached to the organic radicalsadditionally, such substituents as oxygen, sulfur, halogen or nitrosomay also be present.

Aromatic diamines such as the phenylene diamines and the toluenediamines can be employed. Exemplary of the aforesaid amines are:p-phenylene diamine and p-toluene diamine. N-alkyl and N-arylderivatives of the above amines can be employed such as, for example,N,N'-dimethyl-o-phenylene diamine, N'N'-di-p-tolyl-m-phenylene diamine,and p-aminodiphenylamine.

Polynuclear aromatic diamines can be employed in which the aromaticrings are attached by means of a valence bond such as, for example,4,4'-biphenyl diamine, methylene dianiline and monochloromethylenediamine.

The use of amines dissolved in ketones is sometimes desirable because ofbetter control over reaction conditions.

Besides the amines mentioned above, hydrazines and hydrazides can alsobe employed.

Aminoalcohols, mercapto-terminated derivatives and mixtures thereof, andthe like and amino acids can also be employed as the amine. Examplesare: monoethanolamine, 4-aminobenzoic acid, aminopropionic acid,N-(hydroxyethyl) ethylene diamine, antheanilic acid, p-aminophenol,aminostearic acid, and beta-aminobutyric acid. When amino acids areused, appropriate conditions should employed to release reactive aminegroups from Zwitterion complexes.

Further typical amines used to prepare the amine resins includedialkylmonoamines of 1 to 6 carbons in each alkyl group; hydroxyalkylalkyl amines, dihydroxyalkylamines having from 1 to 6 carbons in eachalkyl group; di, tri, tetra and penta amines optionally substituted withalkyl groups of 1 to 6 carbon atoms; aromatic amines such as benzylamine, alkyl substituted benzyl amine; substituted anilines wherein thesubstituent is an alkyl group of 1 to 6 carbon atoms; and nitrogenheterocycles such as pyridine, morpholine, quinoline and the like.Specific examples include methylethanolamine, diethanolamine,triethylenetetraamine, diethylenetriamine and the like

The syntheses of the amine resins follow any of three syntheticprocedures for addition of amine groups to epoxides to form terminatinggroups on epoxy resins. These synthetic procedures are generally knownin the art and include the conventional stoichiometric amine additionprocedure, the "excess amine" procedure and "the diketimine" procedure.

In the conventional stoichiometric procedure, approximatelystoichiometric amounts of amine and epoxide compound are combined in aninert, water-miscible organic solvent or an organic solvent mixture suchas alcohol, methyl isobutyl ketone xylene, toluene, glycol ethers andgently heated to produce amine addition to the terminal epoxide groupsof the epoxide compound. These procedures are known in the art; see forexample U.S. Pat. Nos. 3,984,299 and 4,031,050, the disclosures of whichare incorporated herein by reference.

In the excess amine procedure, approximately an 8 to 12 fold excess ofthe amine on a molar basis is combined with the epoxide compound inaprotic, nonpolar solvent and gently heated to effect addition of theamine to the epoxide groups of the epoxide compound. In this procedure,the presence of excess amine promotes the addition of primary amines andsuppresses the self-addition of amine resin to the epoxide compounds.Upon completion of the reaction, the excess amine is removed by vacuumsteam distillation or other similar appropriate procedure. Theseprocedures are known in the art; see for example, U.S. Pat. Nos.4,093,594, 4,116,900, 4,134,864, 4,137,140, the disclosures of which areincorporated herein by reference.

In the diketimine procedure, a polyamine is typically used where primaryand secondary amine groups are both present. The primary amine groupsare protected as ketimines by reaction of the amine compound with aketone. The secondary amine groups of the diketimine then react with theepoxide groups of the epoxide compound. According to this procedureabout a stoichiometric amount of diketimine is combined with the epoxidecompound in inert organic solvent and gently heated until the reactionis completed. After isolation of the amine resin, the ketimine groupsmay be removed by acid hydrolysis or by aqueous hydrolysis upon standingin water. These procedures are known in the art; see for example, U.S.Pat. No. 3,947,339, the disclosure of which is incorporated herein byreference.

The principal resin emulsions of the invention comprise a mixture of theforegoing amine resins, crosslinking agents and a solubilizing portionof aqueous acid. The preferred ratio by weight of amine resins tocross-linking agents in the principal resin emulsions may be from about2:3 to about 5:1. The amount of water added to the principal resinemulsions is an amount sufficient to provide a solids content of fromabout 10% to about 65% by weight.

The crosslinking agents used in the principal emulsions according to theinvention are blocked organic polyisocyanates or poly (beta hydroxy oralkoxy) esters or other activated polyester compounds, aminoplast resinsor phenoplast resins. In the practice of this invention, it is preferredto use the blocked organic polyisocyanates as crosslinking agents.

All of these crosslinking agents are stable at room temperature but whenheated decompose into compounds which have functional groups that arehighly reactive with alcohol and amine moieties. The crosslinking agentscontain a multiple number of such inchoate groups and will reactmultiple times with the amine resins during hardening so as to crosslinkthe resins into three dimensional matrices.

Typical aminoplast and phenoplast resins used in the art, as disclosedin U.S. Pat. No. 4,139,510, the disclosure of which is incorporated byreference, can be used as crosslinking agents in the practice of thisinvention. Suitable aminoplast resins are the reaction products of ureasand melamines with aldehydes further etherfied in some cases with analcohol. Examples of aminoplast resin components are urea, ethyleneurea, thiourea, melamine, benzoguanamine and acetoguanamine. Aldehydesuseful to form aminoplast resins include formaldehyde, acetaldehyde andpropionaldehyde. The aminoplast resins can be used in the alkylol formbut, preferably, are utilized in the ether form wherein the etherifyingagent is a monohydric alcohol containing from 1 to about 8 carbon atoms.Examples of suitable aminoplast resins are methylol urea-formaldehyderesins, hexamethoxymethyl melamine, methylated polymericmelamine-formaldehyde resins, and butylated polymericmelamine-formaldehyde resins. Aminoplast resins and their method ofpreparation are described in detail in "Encyclopedia of Polymer Scienceand Technology", Volume 2, pages 1-19, Interscience Publishers (1965),the disclosure of which is incorporated by reference.

Phenoplast resins used as crosslinking agents according to the inventionare the reaction products of phenols and aldehydes which containreactive methylol groups. These compositions can be monomeric orpolymeric in nature depending on the molar ratio of phenol to aldehydeused in the initial condensation reaction. Examples of phenols which canbe used to make the phenoplast resins are phenol, o.m. or p-cresol,2,4-xylenol, 3,4-xylenol, 2,5-xylenol, cardanol, p-tert-butyl phenol,and the like. Aldehydes useful in this reaction are formaldehyde,acetaldehyde and propionaldehyde. Particularly useful phenolplast resinsare polymethylol phenols wherein the phenolic group is etherified withan alkyl, e.g. methyl or ethyl, group. Phenoplast resins and theirmethods of preparation are described in detail in "Encyclopedia ofPolymer Science and Technology", Volume 10, pages 1-68, IntersciencePublishers (1969), the disclosure of which is incorporated by reference.

Sufficient quantities of aminoplast and phenoplast resins are used inthe cathodic electrocoat resin compositions to produce sufficientcrosslinking of the modified epoxypolyamine adduct-fatty acid reactionmonoepoxide product upon baking or curing. Typically, the amount ofaminoplast or phenoplast resin used in the practice of this invention isabout 15 weight percent to about 40 weight percent and preferably about20 weight percent about 40 weight percent.

The preferred crosslinking agents used in the practice of this inventionare the organic polyisocyanates and, in particular, the blockedpolyisocyanates. The organic polyisocyanates and the blocking agentsused in the practice of this invention are typical of those used in theart, e.g. U.S. Pat. No. 4,182,831, the disclosure of which isincorporated by reference.

Useful blocked polyisocyanates are those which are stable in theelectrodeposition compositions and baths at ordinary room temperaturesand which react with the amine resin of this invention at elevatedtemperatures.

In the preparation of the blocked organic polyisocyanates, any suitableorganic polyisocyanates can be used. Representative examples are thealiphatic compounds such as trimethylene, tetramethylene,pentamethylene, hexamethylene, 1,2-propylene, 1,2-butylene, 2,3-butyleneand 1,3-butylene diisocyanates: the aliphatic-aromatic compounds such as4,4'-diphenylene methane, 2,4- or 2,6-tolylene, or mixtures thereof,4,4'-toluidine and 1,4-xylylene diisocyanates; the 1,3,5-triisocyanatebenzene and 2,4,6-triisocyanate toluene; and the tetraisocyanates suchas 4,4'-diphenyl-dimethyl methane -2,2', 5,5' tetraisocyanate; thepolymerized dimers and trimers, polymethylenepolyphenylenepolyisocyanates having NCO functionalities of 2 to 3 and the like.

In addition, the organic polyisocyanate can be prepolymer derived from apolyol such as glycols, e.g., ethylene glycol and propylene glycol, aswell as other polyols such as glycerol, trimethylolpropane, hexanetriol,pentaerythritol, and the like as well as monoethers, such as diethyleneglycol, tripropylene glycol and the like and polyethers, i e., alkyleneoxides that may be condensed with these polyols to form polyethers areethylene oxide, propylene oxide, butylene oxide, styrene oxide and thelike. These are generally called hydroxyl-terminated polyethers and canbe linear or branched. Especially useful polyether polyols are thosederived from reacting polyols such as ethylene glycol, 1,3-butyleneglycol, 1,6-hexanediol, and their mixtures; glycerol trimethylolethane,trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol,dipentaerythritol, tripentaerythritol, polypentaerythritol, sorbitol,methyl glucosides, sucrose and the like with alkylene oxides such asethylene oxide, propylene oxide, their mixtures, and the like.

Preferred polyisocyanates include the reaction product of toluenediisocyanate and trimethylolpropane; additionally, the isocyanurate ofhexamethylene diisocyanate.

Any suitable aliphatic, cycloaliphatic, aromatic, alkyl monoalcohol andphenolic compound can be used as a blocking agent in the practice of thepresent invention, such as lower aliphatic alcohols, such as methyl,ethyl, chloroethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, nonyl,3,3,5-trimethylhexanol, decyl and lauryl alcohols, and the like; thearomatic-alkyl alcohols, and the like; the aromatic -alkyl alcohols,such as phenylcarbinol, methylphenylcarbinol, ethyl glycol monoethylether, ethyl glycol monobutyl ether and the like; the phenolic compoundssuch as phenol itself, substituted phenols in which the substituents donot adversely affect the coating operations. Examples include cresol,nitrophenol, chlorophenol and t-butyl phenol.

A preferred blocking agent is monopropyl ether of ethylene glycol.Additional blocking agents include tertiary hydroxyl amines, such asdiethylethanolamine and oximes, such as methylethyl ketoxmine, acetoneoxime and cyclohexanone oxime, and caprolactam. A preferred oxime ismethyl-n-amyl ketoxime.

The blocked polyisocyanates are formed by reacting sufficient quantitiesof blocking agent with sufficient quantities of organic polyisocyanateunder reaction conditions conventional in this art such that no freeisocyanate groups are present when the reaction has run its course.

The blocked organic polyisocyanates generally are known in the art andare described in U.S. Pat. Nos. 3,799,854; 3,984,299 and 4,031,050, thedisclosures of which are incorporated here:n by reference. Additionalblocked polyisocyanates are described in U.S. Pat. No. 4,605,690 thedisclosure of which is incorporated herein by reference. Typically, ablocked polyisocyanate is formed by the combination of an aliphaticpolyol such as trimethylol propane or pentaerythritol, a diisocyanatesuch as toluene diisocyanate and a mono-alcohol such as the monohexylether of ethylene glycol as the isocyanate blocking group. Such anexemplary blocked polyisocyanate typically will deblock at temperaturesof from about 125° to about 190° C.

The poly (beta hydroxy) esters or activated poly esters are generallyknown as transesterification agents. These materials are polyesterswhich have alkylene glycol alkylene glycol monoether, alkylene glycolmonoester or similar moieties as the esterifying group. Upon heating theglycol portion of the ester is lost and the resulting acid moiety reactswith amine or alcohol groups of the amine resin. Usually the polyestermoiety of the beta-hydroxy or beta-activated esters will be a highmolecular weight aliphatic polyacid. Examples generally are poly(2-hydroxyalkyl) esters of polycarboxylic acids. The polycarboxylicacids include, for example, azelaic acid, terephthalic acid, succinicacid and aliphatic di or tricarboxylic acids of 4 to 12 carbons.Alcohols include ethylene glycol, glycerol, trimethylol propane,pentaerythritol and the like. These transesterification agents aredescribed in U.S. Pat. Nos. 4,397,990; 4,401,774; 4,362,847; 4,352,842;4,405,703; 4,405,662; 4,423,167; 4,423,169; 4,489,182, the disclosuresof which are incorporated herein by reference.

The pigment-grind resin formulations employed in the electrodepositioncompositions of the invention are typical and generally known. Thepigment usually will comprise carbon black, titanium dioxide, strontiumdioxide and other pigments necessary for the production of color. Thegrind resins are amine derivatives of epoxy resins of appropriatemolecular weight which will permit the grind resins to function both assurfactant-like compounds and as resinous materials which will combinewith the crosslinkers of the deposited films.

Typical grind resins useful in this regard include the "quaternary"ammonium salts generally disclosed in U.S. Pat. Nos. 3,962,165;4,071,428; 4,530,945; 3,925,180; and 3,936,405 and the "castor oil"grind resins disclosed in U.S. Pat. No. 4,612,338, the disclosures ofwhich are incorporated herein by reference. The procedures, parametersand conditions for preparing the pigment-grind resin formulations andthe proportions and amounts of ingredients necessary are those typicallyused and known in the art. As is appropriate, dibutyl tin oxide is alsoincorporated into pigment grind resin formulation. This ingredient isimportant for promotion of the crosslinking reaction upon baking.

The aqueous electrodeposition compositions are formed from thecombination of the principal emulsions, the pigment-grind resinformulations and water to provide a solid content of from about 10% toabout 65% by weight. The ratio of weights of the pigment-grind resinformulations to the principle resin emulsions are from about 1:10 toabout 2:5. The pH of the electrodeposition compositions may be fromabout 2 to about 8.5 and the ratio by weight of the amine resins tocrosslinking agents in the electrodeposition compositions may be fromabout 2:3 to about 5:1. Likewise the ratio of the pigment to grindresins is from about 2:1 to about 6:1.

Generally, the principal resin emulsions and pigment-grind resinformulations are combined to form the electrodeposition compositionsshortly before use in the electrodeposition baths. The electrodepositioncompositions may be further diluted with water and other components suchas coalescing agents, anti-cratering agents, film build agents,surfactants, antipitting agents and the like to produce the baths.Sufficient quantities of the principal resin emulsions and pigment-grindresin formulations are used so that the coating produced on a substratein the baths will have sufficient thickness so that baking will providesuch desired characteristics as a smooth surface, high build and beeffective in a low temperature cure. In addition, the bath proportionsof compositions should enable short coating time at a low temperature.

The electrodeposition process typically takes place in an electricallyinsulated tank containing an electrically conducting anode which isattached to a direct current source. The size of the tank will depend onthe size of article to be coated. Typically, the tank will beconstructed of stainless steel or mild steel lined with a dielectriccoating such as epoxy impregnated fiberglass or polypropylene. Thetypical size of an electrodeposition tank used for such articles asautomobile or truck bodies will be designed to contain from about240,000 to about 500,000 liters of electrodeposition bath.

Adjustment of deposition parameters such as voltage, the time, the bathtemperature, the percent solids content, the acidity and the like of theaqueous electrodeposition bath in the dip tank will promote appropriatedeposit of the desired film. To this end, a period of immersion of about1 minute to about 4 minutes and a DC voltage for the electric current ofabout 100 volts to about 500 volts and a percent solids in the bath ofabout 18% to about 30% are used with 350 volts voltage, 82° F.temperature, 2 minute period of immersion and 20 percentage of solidsbeing preferred.

After the films have been produced by the electrodeposition process, thefilm-coated substrate bodies are removed from the dip tank and theexcess bath solids are rinsed off. The film-coated substrate bodies arethen placed into an oven where they are cured or hardened. In general,the film-coated substrate bodies are heated to a temperature from about300° F. to 400° F., preferably 325° F. to about 350° F. for a period ofapproximately 20 to about 25 minutes to effect the hardening orcrosslinking reaction. During this process, the film viscosity of theresin systems according to the invention decreases as a result of thehigher temperature and the low film melt viscosity and the films madeaccording to the invention flow so as to provide a uniform coverage ofall areas and surfaces of the substrate body. As the crosslinkingreaction proceeds, film flow ceases and the films eventually becomehardened coatings adhering to the substrate bodies. The hardened coatingthickness produced according to the invention lies in the range of fromabout 16 microns to about 36 microns.

While the hardened coatings derived from the preferred and especiallypreferred classes of amine resins of the invention typically can producefilm thicknesses in the range of about 16 microns to about 24 microns orhigher, the hardened coatings derived from the first and seventhespecially preferred classes of amine resins of the invention, that is,the D2E and 2DEE amine resins, typically will produce "thick build"coatings of about 26 to about 36 microns. These coatings aresubstantially thicker than the standard build coatings typicallyproduced by amine resin-blocked diisocyanate technology practicedaccording to known cathodic electrodeposition processes. Moreover, it issurprising that such "thick build" coatings can be produced in thisfashion since known "thick build" producing components such assurfactants and polyester diols are not incorporated in theseelectrodeposited films according to the invention. Thus, while anincreased film thickness is produced by several of the resin systems ofthe invention, they do not employ a complex additive mixture forincrease of the film build.

The corrosion resistance of the hardened coatings produced by the resincoatings of the invention also are superior, improved and unexpectedrelative to the standard build coatings produced from amine resins andblocked diisocyanates typically employed in cathodic electrodepositiontechnology. Generally, it has been found in scribe or scab testprocedures utilizing metallic panel plates that under a 20 cycle, 20 daytest, involving both humid, hot, cold, dry and salty atmospheres, that acorrosion spread on the order of 2 to 12 millimeters occurs whenhardened resin coatings according to the invention are used. Especiallypreferred in this regard is the hardened coating produced from the 2DEEamine resin. This coating has a corrosion spread of from about 5 to 7millimeters.

It is believed that the unexpectedly improved corrosion resistance foundfor the coatings of the invention is attributable to the betteradhesiveness, lowered glass transition temperature, lowered meltviscosity, flexibility and properties of the amine resins of theinvention. The improved adhesiveness prevents coating undercutting bycorrosive materials such as salt and moisture and prevents peel-up ofthe hardened coatings from the substrate body. The presence of aliphaticgroups within and aliphatic pendant groups from the backbones of theamine resins lower the glass transition temperatures and the meltviscosities of the deposited films. Accordingly, the deposited filmsflow to a greater extent when they are being hardened and, afterhardening, remain more flexible than hardened coatings containing allaromatic groups in the amine resin backbone.

The direct and reverse impact resistance (hereinafter impact resistance)of the coatings of the invention is also superior and unexpectedrelative to the standard build amine resin diisocyanate hardenedcoatings produced by cathodic electrodeposition according to the art. Inthese tests, the hardened coatings according to the invention producedimpact resistance results from about 80 to 160 inch-pounds.

It is believed that the superior impact resistance properties are theresult of the high adhesive character of the hardened coatings formedaccording to the invention. It is hypothesized that the increased numberof hydroxyl groups per molecular weight of amine resin promotes strongbinding of the hardened coatings to the substrate surface. Thisincreased adhesiveness is believed to be the result of hydrogen or othersimilar bonding.

Increased film flexibility also is believed to contribute to direct andreverse impact resistance. The increased flexibility is believed to bederived from the presence of flexible alkyl and alkoxy units within theamine resin backbones. These saturated chain moieties do not impart therigid film characteristics found for the amine resins of the "standardbuild" technology. They are more flexible and avoid the rigidity andbrittleness effects which occur as a result of the use of all aromaticbackbone amine resins.

Articles coated by the compositions according to the invention typicallymay be pretreated to remove impurities and typically are phosphatized.Galvanized metals are typical of the kinds of metallic substrates used;however, the superior corrosion resistivity and impact resistance of theelectrodeposition coatings according to the invention permit the usealso of bare steels without galvanized coatings. Consequently, costsavings are greatly facilitated in the manufacture of coated automobileand truck bodies.

The following examples are illustrative of the principles and practiceof this invention but do not constitute limitations thereof. Parts andpercentages used are parts and percentages by weight.

EXAMPLE 1 A D2E Epoxide

This general procedure was used to prepare a D2E epoxide compound. Thefollowing components were charged into a reaction vessel: the diglycidylether of 2,2-bis (p-butoxy-2-hydroxypropyloxy phenyl) propane, hereafterreferred to as Compound A, the diglycidyl ether of Bisphenol A,Bisphenol A, and toluene. The charge was heated to 290° F. under a drynitrogen atmosphere and 0.3 parts of triphenylphosphine were added tothe reactor vessel. The reaction mixture was further heated to 300° F.and held for 2.25 hours or until the weight per epoxide value of themixture was 1155. The reaction vessel was cooled to 280° F. and 25 partsof methylisobutyl ketone were charged to dilute the reaction mixture.

The following Table 1 lists the proportions of each component chargedfor Examples 1A, 1B and 1C. The addition reaction oligomers produced 1A,1B and 1C were adducts of a Diol D1, Diepoxide E1 and Diepoxide E2.

                  TABLE 1                                                         ______________________________________                                               Com-     Com-     Bis-                                                        pound A  pound B  phenol A                                                                              Toluene                                                                              MIBK                                  ______________________________________                                        Example                                                                              120      80       60.8    13.7   25                                    1A                                                                            Example                                                                              540      360      273.6   61.8   432.7                                 1B                                                                            Example                                                                              450      317.5    232.5   65.0   60.                                   1C                                                                            ______________________________________                                    

EXAMPLE 2 A D3E Epoxide

This procedure prepared a D3E epoxide compound. The following componentswere charged into a suitable reaction vessel: 460 parts of compound A,153 parts of the diglycidyl ether of Bisphenol A, 130 parts ofresorcinol diepoxide, 257 parts of Bisphenol A, and 52 parts of toluene.The charge was heated to 150° C. under a dry nitrogen atmosphere and 0.5parts of triphenylphosphine were added to the reaction vessel. Thereaction mixture was heated to 150° C. for 2.33 hours or until theweight per epoxide value of the mixture was 1164. The mixture was cooledto 100° C. and 210 parts of methylisobutyl ketone was added to diluteit. The oligomer produced was an adduct of Diol D1 and Diepoxides E1, E2and E3.

EXAMPLE 3 A 2DEE Epoxide

This procedure was used to prepare a 2DEE epoxide compound. Thefollowing components were charged to a suitable reactor vessel: compoundA, resorcinol diepoxide, hydroquinone, Bisphenol A, and toluene. Thecharge was heated to 285° F. under a dry nitrogen atmosphere and 0.4parts of triphenylphosphine were added to the reactor vessel. Thereaction mixture was heated to 290° F. and held for two hours or untilthe weight per epoxide value was 1151. The reaction mixture was cooledto 225° F. and 45.2 parts of methylisobutyl ketone were added to diluteit.

The aforementioned procedure and the quantity of components listed intable 2 were used to synthesize the epoxides. The oligomers products, 3Aand B were adducts of Diols D1 and D2 and Diepoxides E2 and E3.

                  TABLE 2                                                         ______________________________________                                        Weight (in parts)                                                                    Com-                     Bis-                                                 pound   Resorcinol                                                                              Hydro- phenol                                        Resin  A       diepoxide quinone                                                                              A      Toluene                                ______________________________________                                        Example                                                                              368     233        40    158.3  42.6                                   3A                                                                            Example                                                                              368     280.5     120    33.3   43.6                                   3B                                                                            ______________________________________                                    

EXAMPLE 4 A 2DE Epoxide

This procedure was used to prepare a 2DE epoxide compound. The followingcomponents were charged into a suitable reaction vessel: 300 parts ofthe diglycidyl ether of Bisphenol A, 60 parts of Bisphenol A, 18 partsof hydroquinone, and 19.9 parts of toluene. The charge was heated to295° F. under a dry nitrogen blanket and 0.4 parts of triphenylphosphinewere added to the reactor vessel. The reactor mixture was further heatedat 310° F. for a period 2.5 hours or until the weight per epoxide valuewas 1197. The mixture was diluted with 51.6 parts of methylisobutylketone. The oligomer produced was an adduct of Diols D1 and D2 andDiepoxide E1.

EXAMPLE 5 A DEE Epoxide

This procedure was used to prepare a DEE epoxide compound. The followingcomponents were charged into a suitable reaction vessel: 332.7 parts ofcompound A, 182 parts of resorcinol diepoxide, 196 parts of Bisphenol A,and 36.8 parts of toluene. The reaction mixture was heated to 300° F.under a dry nitrogen atmosphere and 0.4 parts of triphenylphosphine wereadded to the reaction vessel. The mixture was further heated at 300° F.for five hours or until a weight per epoxide value of 1162 was attained.The reaction mixture was cooled to 210° F. and 41 parts ofmethylisobutyl ketone was added to dilute it. The oligomer produced wasan adduct of Diol D1 and Diepoxides E2 and E3.

EXAMPLE 6 A 2D2E Epoxide

This procedure was used to prepare a 2D2E epoxide compound. Thefollowing materials were charged to a suitable reaction vessel: 294parts of Compound A, 267 parts of the diglycidyl ether of Bisphenol A,35 parts of hydroquinone, 106.3 parts of Bisphenol A, and 37 parts oftoluene. The reaction mixture was heated to 300° F. under a dry nitrogenatmosphere and 0.4 parts of triphenylphosphine were added to reactionvessel. The mixture was further heated at 300° F. for 3.3 hours or untila weight per epoxide of 1154 was obtained. The reaction mixture wascooled to 230° F. and 41 parts of methylisobutyl ketone was added todilute it. The oligomer produced was an adduct of Diols D1 and D2 andDiepoxides E1 and E2.

EXAMPLE 7 A 2D3E Epoxide

This procedure was used to prepare a 2D3E epoxide compound. Thefollowing components are charged to a suitable reaction vessel: 130parts of Compound A, 130 parts of resorcinol diepoxide, 100 parts of thediglycidyl ether of Bisphenol A, 115 parts of Bisphenol A, 25 parts ofhydroquinone, and 25 parts of toluene. The reaction is heated to 300° F.under a dry nitrogen atmosphere and 0.3 parts of triphenylphosphine areadded to the reaction vessel. The mixture is further heated for threehours at 300° F. or until a weight per epoxide of 1146 is attained. Thereaction mixture is cooled to 210° F. and 25 parts of methylisobutylketone are added to dilute it. The oligomer produced was an adduct ofDiols D1 and D2 and Diepoxides E1, E2 and E3.

EXAMPLE 8 Diketimine Adduct

To a suitable reaction vessel equipped with an agitator, a condensorwith a water trap, and a nitrogen line was charged: 1,987 parts ofdiethylenetriamine and 5,788 parts of methylisobutyl ketone. The mixturewas refluxed under a dry nitrogen atmosphere at a temperature <280° F.Water (695 parts) was removed periodically until no more is collected.The mixture was further heated at reflux for one hour and then cooled.

EXAMPLE 9 A Reference ED Epoxide

To a suitable reaction vessel the following components were charged:1,271.4 parts of the diglycidyl ether of Bisphenol A, 455.9 parts ofpolycaprolactone diol, 345.6 parts of Bisphenol A, and 63.3 parts ofxylene. The mixture was heated to 290° F. under a dry nitrogenatmosphere and 2.8 parts of benzyldimethylamine were added. After theexotherm the mixture was heated at 320° F. for 30 minutes or until theweight per epoxide was 650. The reaction was cooled to 260° F. and asecond charge of benzyldimethylamine was added. The vessel was furtherheated at 260° F. until a weight per epoxide of 1150 was obtained. Thepolymer of Example 9 (1565.4 parts) was quickly added cooling thereactor temperature to 200-210° F. The amine of Example 8 (128.3 parts)was added to the mixture followed by 103.1 parts of methylethanolamine.The reaction mixture was heated to 240° F. for one hour. Hexylcellosolve(132.8 parts) was added to dilute the mixture.

EXAMPLE 10 Ordered DEE Epoxide 1

To a suitable reaction vessel was charged the following components:213.7 parts of resorcinol diepoxide, 227.3 parts of Bisphenol A, and 50parts of toluene. The mixture was heated to 150° C. under a dry nitrogenatmosphere and 0.4 parts of triphenylphosphine were added. After theexotherm the mixture was further heated at 150° C. for 2.5 hours. Thereaction vessel was cooled to 130° C. and 30.1 parts of toluene wereadded. After cooling to 120° C., 361 parts of compound A was added. Themixture was heated to 150° C. and held at that temperature for two hoursor until a weight per epoxide of 1270 was obtained. The mixture wasdiluted with 100 parts of methylisobutyl ketone.

EXAMPLE 11 Ordered DEE Epoxide 2

To a suitable reaction vessel was charged the following components:361.8 parts of Compound A, 227.4 parts of Bisphenol A, and 56 parts oftoluene. The mixture was heated to 150° C. and 0.4 parts oftriphenylphosphine were added. The mixture was further heated at 150° C.for two hours. The vessel was charged with 213.9 parts of resorcinoldiepoxide an 40.9 parts of toluene. The vessel was further heated at150° C. for three hours or until weight per epoxide of 1100 wasobtained. The mixture was diluted with 100 parts of methylisobutylketone.

Example 12 Stoichiometric Amine Resin Preparation

A suitable reaction vessel containing the upgraded epoxide compound fromExample 1-7 was placed under a dry nitrogen atmosphere and heated to200°-220° F. Methylethanolamine (MEOA) was charged to the flask underagitation and further heated at 200°-220° F. for a period of 2.5 hours.Methylisobutyl ketone was charged to dilute the mixture.

Using the aforementioned procedure the quantity of epoxide compound andMEOA amine listed in Table 3 was used to synthesize the amine resinexamples 12A-12H which correspond to the epoxide compounds of Examples1-7.

                  TABLE 3                                                         ______________________________________                                        Amine Resins                                                                             Epoxide                                                                       from     Epoxide  MEOA   MIBK                                      Amine Resin                                                                              Example  Parts    (parts)                                                                              (parts)                                   ______________________________________                                        12A (D2E)  Example  299.8    16.9   110.8                                                1A                                                                 12B (D3E)  Example  1052.5   65     528                                                  2                                                                  12C (2DEE) Example  888.1    52.1   369.6                                                3A                                                                 12D (2DEE) Example  890.9    52.1   370.7                                                3B                                                                 12E (2DE)  Example  449.5    23.7   104.2                                                4                                                                  12F (DEE)  Example  778.6    44.9   323.7                                                5                                                                  12G (2D2E) Example  739.7    45.7   324.8                                                6                                                                  12H (2D3E) Example  500      32.6   187                                                  7                                                                  ______________________________________                                    

EXAMPLE 13 "Excess Amine" Amine Resin Preparation

A conventional reactor equipped with an agitator, a dry nitrogen line,and a condensor was charged with 950 parts of triethylenetetramine. Thetriethylenetetramine was heated 55° F. Then, 1634.7 parts of the adductof Example 1B were charged to the vessel and heated to 200° F. for onehour. Next, the excess amine in the reactor mixture was vacuumdistilled, condensed, and removed by applying a vacuum of 75 mm Hg andslowly raising the temperature to 470° F. over four hours. The mixturewas held at the temperature until no more distillate was coming out. Thetemperature was then lowered to 300° F. and 158.7 parts of pelargonicacid along with 125 parts of xylene were added to the reaction vessel.The reaction mixture was heated to 410° F. and held at reflux until theacid value was down 3.2. Then the reaction mixture was cooled to 270° F.and 648.8 parts of methylisobutyl ketone were added to dilute it.

EXAMPLE 14 "Ketimine" Amine Resin Preparation

A suitable reaction vessel equipped with a dry nitrogen line,thermometer, and agitation was charged with 1066 parts of the adduct ofExample 1C. The mixture was heated to 100° C. The diketimine ofdiethylenetriamine (152.6 parts) and methylethanolamine (31.3 parts)were charged to the vessel and heated at 120° C. for one hour. Themixture was cooled and diluted with methylisobutyl ketone to 65% N.V.

EXAMPLE 15 Blocked Diisocyanate Cross-Linking Agent

The primary crosslinking agent was prepared by slowly charging 870 partsof trimethylolpropane into a suitable reactor vessel containing 3387parts of an 80/20 isomer mixture of 2,4-/2,6-toluene diisocyanate, 1469parts of methylisobutyl ketone, and 2 parts of dibutyl tin dilaurateunder agitation with an nitrogen blanket. The reaction was maintained ata temperature below 110° F. The charge was held an additional one andone-half hours at 110° F. and then heated to 140° F. at which time 2026parts of ethylene glycol monopropyl ether was added. The charge wasmaintained at 210° F. to 220° F. for one and one-half hours untilessentially all of the isocyanate moiety was consumed as indicated byinfrared scan. The batch was then thinned with 2116 parts of methylisobutyl ketone.

EXAMPLE 16 Blocked Diisocyanate Cross-Linking Agent

An 80/20 mixture of 2,4/2,6-toluene diisocyanate (2949 parts) wascharged to a suitable reaction vessel under a dry nitrogen atmosphere.2-Ethylhexanol (2209.4 parts) was added to the vessel under agitation ata suitable rate to keep the vessel temperature below 120° F. After theaddition is complete, the mixture is stirred for 30 minutes or until anisocyanate equivalent weight of 285-325 is obtained. Dibutyltindilaurate (0.9 parts) was charged to the vessel and the mixture washeated to 150° F. Trimethylolpropane (264.7 parts) was added at asuitable rate to keep the temperature below 250° F. After addition, themixture was further heated at 250° F. for 1.5 hours. A mixture ofmethylisobutyl ketone (2282.4 parts) and n-butanol (253.6 parts) wascharged to the vessel to dilute the mixture.

EXAMPLE 17 Castor Oil Grind Resin

The grind vehicle was prepared by adding the following components to asuitable reactor vessel: 2280 parts of Iris (glycidyl ether) of castoroil Epi-Rez 505 TM (WPE° 600) manufactured by Celanese Corporation,Louisville, Ky., to a mixture of 331 parts of monobutyl ethylene glycolether, and 619 parts of polyglycolamine H-163, at 77° C. for 1.5 hour.The reaction temperature was held at 115° C. for one hour.

EXAMPLE 18 Pigment Paste

A pigment paste was prepared by grinding 123 parts of the grind vehicleof Example 17, 8 parts of acetic acid, 252 parts of deionized water, 4parts of dibutyl tin oxide, 17 parts of carbon black, 56 parts of leadsilicate, and 145 parts of clay in a suitable mill for about one-halfhour until the average particle size was less than about 12 microns, (atambient temperature).

EXAMPLE 19 Pigment-Grind Resin Foundation

The products of example 19 and Example 20 are the two intermediates forthe grinding vehicle. Example 19 was prepared by charging ethyleneglycol monopropyl ether to 2,6-toluene diisocyanate under agitation witha dry nitrogen blanket. The reaction was maintained at a temperaturebelow 100° F. The charge was held an additional one and one-half hour.

EXAMPLE 20 Grind Resin

In a suitable reactor vessel, 455 parts of a alkylaryl polyether alcohol(Triton X-102TM manufactured by Rohm and Haas, Philadelphia, Pa.) and 51parts of methyl isobutyl ketone previously azeotroped to remove water,were added to 109 parts of 2,4-toluene diisocyanate. The reaction wasmaintained at 115° F. for 2 hours. Then 56 parts of dimethylethanolamine were charged, and the reaction was maintained at 160° F.for 1 hour. Finally, 50 parts of ethylene glycol monobutyl ether, 75parts of lactic acid, and 89 parts of deionized water were charged, andthe reaction was held at 190° F. for one hour.

EXAMPLE 21 Grinding Vehicle

The grinding vehicle was prepared by charging 88 parts of the adduct ofExample 19 to a reaction vessel containing 206 parts of diepoxy adductof bisphenol A and its bisglycidyl ether EPON 1002F(WPE° 650manufactured by Shell Chemical Co., Houston, Tex.) and 39 parts ofmethyl isobutyl ketone. The reaction temperature was maintained at 250°F. for one hour. Ethylene glycol monobutyl ether, 186 parts, and theadduct of Example 20, 381 parts, were added. The batch was maintained at180° F. for four hours.

EXAMPLE 22 Pigment Paste

A pigment paste was prepared by grinding 1081.1 parts of Example 21,2,208.5 parts of deionized water, 1,947.4 parts of clay, 272 parts ofcarbon black, 341.4 parts of lead silicate, and 77.6 parts of dibutyltinoxide in a steel ball mill for 15 minutes. Strontium chromate (172.4parts) was blended into the mill. The mixture was ground for about 24hours so the maximum particle size was 16 microns. An additional 324.8parts of Example 21 and 116.8 parts of deionized water were added to themill and ground for three hours.

EXAMPLE 23 Anti-Cratering, Flow Agent

The acrylic anti-cratering agent was prepared by charging 44 parts ofbutyl acrylic, 15 parts of hydroxyethyl acrylic, 15 parts ofdimethylaminoethyl methacrylic, 2 parts of styrene, 1 part of octylmercaptan, 4 parts of 2,2'-azobis-(2-methyl butyronitrile), (apolymerization initiator) Du Pont VAZO 67, and 3 parts of acetone to arefluxing mixture of 13 parts of methyl isobutyl ketone and 2 parts ofacetone over a 4 hour period. After a 15 minute holding period, 0.14parts of Du Pont VAZO 67 and 1 part of methyl isobutyl ketone was added.The batch was maintained at the refluxing temperature for another hour.

EXAMPLE 24 Principal Emulsion

Principal emulsions were prepared by adding 817.2 parts of the amineresin of Example 12, 411.2 parts of the crosslinker of Example 15, 18.3parts of acetic acid, 22.9 parts of the acrylic flow agent of Example23, 28.9 parts of phenyl cellosolve, and 449 parts of deionized waterand high agitation for one hour. An additional 792 parts of deionizedwater was added. After agitation for two days, organic solvents weredriven off.

Following the foregoing procedure, substituting the epoxy/amine resinadduct of Example 1A with epoxy/amine adducts of Examples 12B-12H and14, principal emulsions incorporating the amine resins of Examples12B-H, 14 were prepared as described in Table 4.

                                      TABLE 4                                     __________________________________________________________________________              Principal Emulsion No.                                                        23A 23B  23C  23D  23E  23F  23G  23H                               __________________________________________________________________________    Amine Resin                                                                             12B 12C  12D  12E  12F  12G  12H   14                               Example No.                                                                   Crosslinker                                                                             386.6                                                                             431.8                                                                              421.0                                                                              431.9                                                                              393.2                                                                              417.3                                                                              420  426.1                             Acetic Acid (25%)                                                                       76.0                                                                              82.8 91.2 84.9 74.3 71.5 71.5 102.8                             Phenyl Cellosolve                                                                       28.0                                                                              30.1 29.4 29.9 27.4 29.1 30.0  29.0                             Deionized Water                                                                         465 1416.5                                                                             1359.4                                                                             1311.7                                                                             1280.5                                                                             1455.3                                                                             1454.1                                                                             1428.5                            Resin     750.0                                                                             831.6                                                                              809.6                                                                              817.3                                                                              775.6                                                                              831.6                                                                              834.2                                                                              844.5                             __________________________________________________________________________

EXAMPLE 25 Principal Emulsion

The principal emulsion was prepared by adding 619.8 parts of the amineresin of Example 13, 413.2 parts of the crosslinker of Example 16, 137.4parts of polycaprolactone diol, 28.5 parts of the acrylic flow agent ofExample 23, 9.1 parts of acetic acid, and 1165.3 parts under highagitation for one hour. After agitation for two days, organic solventswere driven off.

EXAMPLE 26 Reference Principal Emulsion

The polymer mixture of Example 9 (4071.4 parts) was charged into asuitable vessel containing 64.4 parts of 25% acetic acid, and 3,079.6parts of deionized water over a 20 minute period with high agitation.The mixture was further stirred for one hour. An additional 1555.6 partsof deionized water was added.

EXAMPLE 27 Reference ED Bath

A cationic electrodepositable paint (bath) was prepared by blending 840parts of deionized water, one part of 25% acetic acid, 1,388 parts ofExample 26 and 264.8 parts of Example 22. An additional 706.2 parts ofdeionized water is added to the mixture. Bare cold-rolled steel and barehot-dipped galvanized panels were plated at 325V. for two minutes gavesmooth films of 0.6-0.8 mil. thickness after a 350° F. bake for 25minutes.

EXAMPLE 28 Electrodeposition Baths

A cationic electrodepositable paint (bath) was prepared by blending1523.6 parts of the principal emulsions of Example 25, 1,923.8 parts ofdeionized water, and 352.6 parts of the adduct of Example 26. The bathhad a pH of 6.5 and a total solid content of 20%. Bare cold-rolled steeland bare hot-dipped galvanized panels were plated at 270V for twominutes gave smooth films of 0.9-1.0 mil thickness after a 325° F. bakefor 25 minutes.

Using the foregoing procedure, the principal emulsions of Examples 23A-Gwere incorporated into electrodeposition baths and electrodeposited asdescribed.

EXAMPLE 29 Corrosion Resistance Test

Electrodeposited panels of Example 28 were scribed and subjected to the20 cycle GM scab corrosion test. One cycle consisted of a 24 hour periodin which the coating was soaked in an ambient temperature 5% saltsolution, dried and placed in 140° F./85% relative humidity cabinet Ahot/cold cycle was incorporated into cycles 1, 6, 11, and 16 by whichthe panel was heated to 140° F. and then cooled to 15° F. After the 20cycle scab test the panels were blown off with compressed air and werescraped to remove any loose coating.

Using the foregoing procedure of Example 29 and the electrocoated panelsobtained from the paints of Example 28, the panels were evaluated asdescribed in the foregoing procedure. Results are summarized in Table 5.

                  TABLE 5                                                         ______________________________________                                        Corrosion Resistance                                                                       Full Width                                                                    Scribe Creep (mm)                                                Electrocoat Bath                                                                             Bare Steel                                                                              Bare Galvanized                                      ______________________________________                                        28A            6.6       7.6                                                  28B            6.7       5.7                                                  28C            6.6       5.5                                                  28D            12.1      *                                                    28E            7.4       5.0                                                  28F            6.5       7.2                                                  28G            6.8       3.4                                                  27             9.7-10.3  4.2-4.9                                              ______________________________________                                         *Result was not available.                                               

We claim:
 1. A 2DE epoxide compound comprising the addition reactionoligomer of monomers Diol D1, Diol D2 and Diepoxide E2 wherein:Diol D1has at least two aryl groups between the hydroxyls, Diol D2 has only onearyl group between the hydroxyls, and Diepoxide E2 is a bis(glycidyleither) of a bis(labile hydrogen functionalized alkoxy) arylene.
 2. A2DE epoxide compound according to claim 1 wherein dio D1 is a bis(arylalcohol) compound.
 3. A 2DE epoxide compound according to claim 1wherein Diol D2 is an aryl diol.
 4. A 2DE epoxide compound according toclaim 1 wherein:Diol D1 has the formula HO--Ar¹ --OH, Ar¹ being anaphthalene group or a polyphenylene group having two or threephenylenes linked by carbon-carbon bonds or alkylene groups of 1 to 5carbons, or a substituted derivative of said naphthalene orpolyphenylene group, said substituent being halogen, alkoxy of 1 to 3carbons, or alkyl of 1 to 3 carbons; Diol D2 has the formula HO--Ar³--OH, Ar³ being a phenylene or substituted phenylene, the substituentbeing halogen, alkoxy of 1 to 3 carbons, or alkyl of 1 to 3 carbons; andDiepoxide E1 has the formula ##STR5## Ar¹ being as defined for Diol D1.5. A 2DE epoxide compound according to claim 1 wherein the diepoxidemonomer and diol monomers alternate in sequence in the oligomer and thedistributions of Diepoxide E2, and Diols D1 and D2 in the oligomer arerandom.
 6. A 2DE epoxide compound according to claim 1 wherein thediepoxide monomer and diol monomers alternate in sequence in theoligomer and the distribution of monomers is ordered so as to provideblocks of Diepoxide-Diol: E2-D1 and E2-D2.
 7. A 2DE epoxide compoundaccording to claim 1 wherein the ratio of Diol D1 and D2 equivalents tothe sum of Diepoxide E2 equivalents is calculated to yield an oligomermolecular weight of from about 900 to about 4000, equivalents being themolecular weight of diol or diepoxide divided respectively by the numberof hydroxyls groups or epoxide groups present in the diol or diepoxide.8. A 2DE epoxide compound according to claim 1 wherein Diol D1 isp,p-dihydroxydiphenyl alkane of 1 to 3 carbons, p,p-dihydroxydiphenyl,1,5-dihydroxynaphthalene or bis(hydroxynapthalene) methane and Diol D2is resorcinol, hydroquinone or catechol.
 9. A 2DE amine resin comprisingthe reaction product of:A) the 2DE epoxide compound of claims 1, 2, 3,4, 5, 6, 7 or 8; and B) an amine.
 10. An amine resin according to claim9 wherein the amine is ammonia, a mono- or poly- organic amine havingprimary, secondary, or tertiary groups or combinations thereof, or aheterocyclic amine or a physical blend or chemical mixture of saidamines.
 11. An amine resin according to claim 9 wherein the aminecontains hydroxy, ether, alkoxy, thio, thioether, carboxyl or amidegroups.
 12. An amine resin according to claim 9 wherein the amine is amono or poly aliphatic, aromatic or alkaromatic amine having from 1 to 6primary, secondary, tertiary groups or a combination thereof, or aheterocyclic amine.
 13. A 2DE principal resin emulsion comprising water,an acid solubilized 2DE amine resin according to claim 9 and across-linking agent.
 14. A principal emulsion resin according to claim13 wherein the cross-linking agent is a blocked organic polyisocyanate.15. An aqueous electrodeposition composition comprising a principalresin emulsion according to claim 13 and a pigment-grind resinformulation wherein the grind resin is a quaternary ammonium salt, or anesterified, alkoxylated aliphatic amine.
 16. An aqueouselectrodeposition composition according to claim 15 wherein the solidscontent is about 10% to about 65% by weight, the ratio of weight ofpigment-grind resin formulation to the sum of the weights of amine resinand cross-linking agent is from about 1:10 to about 2:5; the pH is about2 to 8.5, the ratio by weight of amine resin to cross-linking agent isfrom 2:3 to 5:1 and the ratio by weight of pigment to grind resin isabout 2:1 to about 6:1.
 17. A method of coating a substrate comprisingcathodically electrodepositing onto the substrate a 2DE amine resinaccording to claim 9.